Yuskaitis Christopher J, Jope Richard S
Department of Psychiatry and Behavioral Neurobiology, 1720 Seventh Avenue South, Sparks Center 1057, University of Alabama at Birmingham, Birmingham, AL 35294-0017, USA.
Cell Signal. 2009 Feb;21(2):264-73. doi: 10.1016/j.cellsig.2008.10.014. Epub 2008 Oct 29.
Microglia play a prominent role in the brain's inflammatory response to injury or infection by migrating to affected locations, secreting inflammatory molecules, and phagocytosing damaged tissue. However, because severe or chronic neuroinflammation exacerbates many neurological conditions, controlling microglia actions may provide therapeutic benefits in a diverse array of diseases. Since glycogen synthase kinase-3 (GSK3) promotes inflammatory responses in peripheral immune cells, we investigated if inhibitors of GSK3 attenuated microglia responses to inflammatory stimuli. Treatment of BV-2 microglia with GSK3 inhibitors greatly reduced the migration of microglia in both a scratch assay and in a transwell migration assay. Treatment of BV-2 microglia with lipopolysaccharide (LPS) stimulated the production of interleukin-6 and increased the expression of inducible nitric oxide synthase (iNOS) and NO production. Each of these microglia responses to inflammatory stimulation were greatly attenuated by GSK3 inhibitors. However, GSK3 inhibitors did not cause a general impairment of microglia functions, as the LPS-induced stimulated expression of cyclooxygenase-2 was unaltered. Regulation of microglia functions were also evident in cultured mouse hippocampal slices where GSK3 inhibitors reduced cytokine production and microglial migration, and provided protection from inflammation-induced neuronal toxicity. These findings demonstrate that GSK3 promotes microglial responses to inflammation and that the utilization of GSK3 inhibitors provides a means to limit the inflammatory actions of microglia.
小胶质细胞通过迁移至受影响部位、分泌炎症分子以及吞噬受损组织,在大脑对损伤或感染的炎症反应中发挥重要作用。然而,由于严重或慢性神经炎症会加剧许多神经系统疾病,控制小胶质细胞的活动可能为多种疾病带来治疗益处。鉴于糖原合酶激酶-3(GSK3)在外周免疫细胞中促进炎症反应,我们研究了GSK3抑制剂是否能减弱小胶质细胞对炎症刺激的反应。用GSK3抑制剂处理BV-2小胶质细胞,在划痕试验和Transwell迁移试验中均大大减少了小胶质细胞的迁移。用脂多糖(LPS)处理BV-2小胶质细胞会刺激白细胞介素-6的产生,并增加诱导型一氧化氮合酶(iNOS)的表达和一氧化氮的产生。GSK3抑制剂大大减弱了这些小胶质细胞对炎症刺激的反应。然而,GSK3抑制剂并未导致小胶质细胞功能的普遍受损,因为LPS诱导的环氧化酶-2的刺激表达未发生改变。在培养的小鼠海马切片中也明显观察到了小胶质细胞功能的调节,其中GSK3抑制剂减少了细胞因子的产生和小胶质细胞的迁移,并提供了对炎症诱导的神经元毒性的保护。这些发现表明,GSK3促进小胶质细胞对炎症的反应,并且使用GSK3抑制剂提供了一种限制小胶质细胞炎症作用的方法。